1. Field of the Present Invention
The present invention relates generally to breath condensate collection, and more particularly, to full-featured breath condensate collection apparatuses capable of separating the expired airway phase of mammalian exhalation from the alveolar phase.
2. Background
As is well known, exhaled breath condensate contains water-soluble and water insoluble molecules, including dissolved gases, organic solutes, ions and proteins. Analysis of the molecular content of breath condensate can provide a method to diagnose and prognose certain diseases. (S. A. Kharitonov and P. J. Barnes, Exhaled markers of pulmonary disease, Am J Respir Crit Care Med 163:1693-1722, 2001.) However, the measurement of substances in exhaled condensate as a method to determine the presence of pathophysiologic processes in the lung alveoli is degraded by contamination by substances arising from the mouth, nose, throat and the tracheobronchial tree. Using two dimensional gel electrophoresis, Griese and colleagues demonstrated distinctly different proteins in breath condensate collected from oral breathing, compared with nasal breathing (M. Griese, Proteomics 2:690-696, 2002.) This contamination can cause false positive testing.
It is our hypothesis that a gating mechanism can be triggered from the measurement of the partial pressure of carbon dioxide in exhaled breath to open and close during the exhalation cycle in a manner to separate out the contaminant breath volume, generated during the expired airway phase of the exhalation cycle, from the alveolar volume generated during the alveolar phase of the cycle. The ability to selectively collect alveolar breath condensate rapidly and easily with a point-of-care device would improve the clinical utility of breath-based diagnosis for this purpose, particularly in the emergency department or clinic setting. The device described is designed to allow a patient to breath into a handheld disposable chamber to facilitate the collection of breath water vapor which can then be analyzed for biochemicals to detect the presence of specific diseases, including bacterial, chlamydial, mycoplasma, or fungal pulmonary infection, pulmonary embolism, pulmonary ischemia, systemic gram negative sepsis, fat embolism from sickle cell disease or after surgical fixation of fractures, carcinoma of the lung, asthmatic inflammation, and chronic obstructive pulmonary disease.